Mixing machine



H. L. JOHNSTON ET AL MIXING MACHINE Filed Jan. 18, 1922 3 Sheets-Sheet 1 NV NT OR5 ATTORNEYS Aug. 4, 1925. v

MIXING MACHINE 3 Sheets-Sheet 2 Filed Jan. 18, 1922 A froze/v5 m V NVLNTORJ Aug. 4, 1925. 1,548,041

H. L. JOHNSTON ET AL MIXING MACHINE Filed Jan. 18, 1922 3 Sheets-Sheet 3 1N VENTORJ A 770/: NE 1;

Patented Aug. 4, 1925.

UNITED STATES g 1,548,041 PATENT OFFICE.

nnnnnnr 1.. JOHNSTON Am) marrow K. AIKERS, or raw, omo, Assrenons TO THE HOBART MANUFACTURING con'rANY, or TROY, 01110, A conroiwnon or 01110.

mime 'MACIIINE.

Application filed January 18, 1922. Serial 1T0. 530,158.

' lowing is a full, clear, and exact description,

reference being had to the accompanying v drawings, forming part of this specification.

Our machine relates to that type of cake mixing machine which is usually driven by an electric motor and is provided with change'of speed mechanism for varying the speed of the beater and the object of the 1n vention is to provide various features of novelty to be hereafter particularly pointed out and claimed, whereby the operation of the various parts will be safeguarded and rendered more effective and convenient.

One of the points of novelty relates to a simple and effective arrangement for interlocking the gear speed change devlces for changing the speed with the switch control for the motor, whereby the current for the motor cannot beturned on untilthe gear shifting devices are in proper posltlon, nor the gears shifted from one'positlonto another while the current is on and the motor in operation.

Another feature of novelty relatesto the system of lubrication, whereby the oil 1s lifted from the bottom of the case and discharged overthe gearing to run back to the bot-tom and to be repum'ped so as to malntain a continuous circulation of lubricant and in which system two of the driving train of gears may be utilized as a gear pump.

A third feature relates to the construction employed for coupling the driving shaft to the driven shaft to absorb the shocks incident to the sudden startingof the machine and also to the manner of securing the planetary element to the driving shaft, so that the connection can be broken without other damage to the mechanism in the event of a sud- In the drawings,

Figure 1 is a central vertical section of the complete machine.

Figure 2 is a top plan view with the electric motor removed.

Figure 3 is a detail elevation of the transmission gears, partly in section.

Figure 4 is a perspective view of the main driving gear for the main driving shaft.

Figures 5 and 6 are perspective views of the coupling pieces for the drivin shaft.

Figure 7 is a front elevation of the interlocking device for the change of speed mechamsm.

Figure 8 is a longitudinal section of the same.

Figure 9 is a cross section of the shifting device.

Figure 10 is a perspective View of one of the bowl handles and connecting devices.

The machine is mounted on a substantial base 1 carrying a pedestal 2 and gear case 3, these parts toget er providing a substantial framework for the working parts.

Mounted on top of the gear case is the electric motor 4 with its motor shaft 5 projecting downwardly and carrying a pinion 6. This pinion meshes with a, drlving gear 7 mounted on the driving shaft 8 of the machine mounted vertically in suitable bearings in the gear case. The lower end of the shaft carries the pinion 9, which meshes with the gear 10 keyed to the lower end of a countershaft 12, which carries loosely mounted thereon three gears of different diameters 13, 14 and 15. The construction for selectively coupling any one of these gears to the countershaft for varying the speed will be sheared off to free the planetary head and relieve the motor and transmission. mechanism from undue anddangerous strains, and consequent damage.

Mounted in the planetary head a suitable distance from the shaft 19 and parallel thereto is the beater shaft 22, to which any desired shape of beater can be attached. In orderthat this beater shaft shall be rotated on its own axis, the shaft carries a pinion 23,

which meshes with an internal gear on the ring or band 24 secured to the gear casing. In this way the usual planetary movement is imparted to the beater. When a mere rotary movement for the beater without rotation on its axis is desired, we provide a shaft 25 secured in fixed position in the planetary head.

In order to vary the speed of the beater we provide for selectively coupling the gears 13, 14 and 15 to the countershaft 12 by means of a key-way 26 and sliding key 27 provided with a projection 28 to engage in a key-way in the bearing face of the gear selected.

The key 27 is attached to the grooved collar 29, mounted to slide on the shaft 12 and actuated by the yoke 30 pinned on the rod or shaft 31, which is adapted to be rocked by the handle 32.

Attached to this handle is a segmental plate 33 provided with a series of notches 34. This plate extends up in front of the switch box 35, through which the current to the motor is furnished through the wires 36, 36". The current is controlled by the switch lever 37 which projects out through the box and is depressed to throw on the current and raised to cut it off. This lever must therefore enter one of the notches on the plate 33 before current can be supplied to the motor and therefore the gear shifting handle must be moved into such position that one of the gears in the speed train will be properly connected before the motor can be started. The switch lever when seated in one of the notches 34 also blocks the handle from movement to another position while the current is on, so that it is impossible to change the speed except when the current is turned ofl".

To provide a simple and effective system of lubrication we utilize the gears 9 and 10 for the gear pump. These gears are enclosed in a casing 37 to form the pump casing, and a tube 38 connects one side of the casing with the oil supply in the bottom of the transmission casing. On the delivery side of the gear pump casing the oil is raised through the pipe 40 and discharged over the transmission gears in the upper part of the casing. The oil from this point runs down over the gear mechanism and is distributed throughout the casing, finally collecting in the bottom 39, whence it is again pumped through the system.

In order to provide a shock absorber to avoid shocks from the sudden startin of the motor, We provide a limited yiel ing connection between the motor and driving shaft.

1 The gear 7 is formed with an elongated hub 41 provided with an axial slot 42. The shaft 8, upon which the gear 7 is mounted,

carries a stud screw 43 Secured in the hole 44 in the shaft, which stud projects through the slot 42 in the hub of the gear, and this stud also engages in the notch 45 provided in a split sleeve 46, which is slipped over the hub and is provided with a turned-in portion 48 which engages in the slot 42.

In this way the gear 7 is secured to the shaft 8. Any sudden starting of the motor throws a. heavy torsional strain between the gear 7 and the shaft 8 and under this strain the split sleeve, which is of resilient material, will open out, within the limits of play of the stud 43, and act as a cushion to absorb the shock.

The machine is provided with devices for holding and raising and lowering the bowl 550 of familiar construction.

The construction comprises a sleeve 51 mounted on the pedestal 2 and raised or lowered by the handle 52 coupled to the sleeve by the connecting rod 53. The sleeve 51 is formed with arms 54 constituting a semi-circular open frame in which the mixing bowl is seated.

The bowl is provided with a handle 55 on each side for transporting the bowl, and the lower end of the handle has a projecting flange 56 with a hole in it to fit over an upwardly projecting pin 57 on the outer end of each segment arm 54. This construction of handle provides not only a simple and effective handle, but the pins 57 being located in axial alignment with the shaft for the beater head, a simple method is provided for centering the bowl in the axis of rotation of the mixing mechanism.

Projecting laterally from the arms is also located a pin 58, from which can be suspended a vessel 59 for holding heating or cooling mediums'in which it may be desired to partially immerse the mixing bowl for heating or cooling the ingredients.

' For securing the various styles of beaten; to be used in the end of the beater shaft we employ a bayonet lock construction in which the beater is provided with a socket 61 to fit closely over the end of the shaft. The socket is provided with an L-shaped slot 62 terminating in a notch 63 which is engaged by a pin 64 on the. shaft, while to maintain the engagement and to prevent the beater from becoming accidentally disengaged we provide a coiled spring64 interposed between the socket of the beater and a washer on the shaft.

In order to utilize the machine for other attachments, such as grinders, choppers, and the like, the main vertical shaft is provided in the gear casing with a beveled gear 65 meshing with a corresponding beveled gear 66 on the horizontal shaft 67. This shaft has its bearin in a housing 68 where provision is made far coupling the driving shaft of the attachment.

The operation of the mixing machine will be obvious from the foregoing description. It will be understood, of course, that in the description of details of mechanism We have only shown our preferred form, that we do Having thus described our invention,

what we claim as new and desire to secure by Letters Patent, 'is: v v

1. In a mixing machine, the combination of a bowl support with upwardly projecting pins on the outer ends thereof, and a mixing bowl to be supported thereon, the mixing bowl provided with handles having horizontal flanges with openings therein to IQCBlXG the pins on the arms for securing and centering the bowl.

2. In amixing machine, the combination of a bowl support with upwardly'projecting pins on the outer ends thereof, and a mixing bowl to be supported thereon, the mixing bowl provided with one piece handles attached to the bowl and provided with projecting horizontal flanges With openings therein to receive the pins on the arm for securing and centering the bowl.

HERBERT L. JOHNSTON. MILTON K. AKERS. 

